Printing-telegraph system



W. A. @Mmmm TELEGRAPH SYSTEM PRINTING Filed July 3.9. 19527 d AWM/mwPatented July 23, 1929.

. 1,722,050 uNrrED.--S-TATEs PATENT OFFICE.

W1LLIAM"n.'.xNooP, or HEMEs'rEAn, NEW YQEK, AssIGNoETo WESTERN ELECTRICCOMPANY, INCORPORATED, oENEW YORK, N. Y., A CoEroRATIoN or NEW YORK.

.'PRINTINGFTELEGRAPH SYSTEM.

App1ication. tiled July 19,

This invention'relates to transmission. systems and more particularly-te high speed printing telegraph systemsemploying long lines such assubmarine cablesand the like.

An object of the invention is to insure the operationof printer magnets'in response to signals transmitted over a long line adapted for highspeed transmission.

' A more specific object ofthe invention is to lengthen transmittedsignal impulses at the receiving station suliciently tooperate .theprinter magnets Without impairing the high speed efficiency of a loadedsubmarine cable.

In' certain types of telegraph systems, par# ticularly thesystemsadapted for thehigh speed transmission, means have been emplqyedintermediate the transmitting appa-` ratus'and the line or cable, forrelaying the transinitted signals to the line or cable, such means beingCapable ot regulating the amoilint and duration of current entering thelineor cableat each signal impulse Without imposing any limitations onthe speed at which the telegraph signals are transmitted.

These means comprise a three-electrode electric discharge device, suchas the well known ting apparatus.

audion or thcrmionic relay, operatin g by pure electron discharge, orsimilar threefelement tube operating with ionized gas, and anelectrostatic element, such as a condenser, connected in the inputcircuit of the discharge device and designed to be charged in accordancewith the actuation of suitable transmit- When the condenser possesses acharge, a potential will be applied .to the grid electrode of theelectric discharge device, which is of sufficient-value to allow currentto :fiow in the plate circuit, thereby applying a definite transmittingpotential to the line or cable. Since the input circuit of the dischargedevice is of an extremely highu resistance, the condenser will'discharge very slowly, thereb f maintaining a How of current in the lineas ong as the condenser retains a charge.

According to'the" present invention, the signal impulses arelengthenedatthe receiving station to allow the use of a relatively cheap,slow-speed printer selector magnet. Each impulse is lengthened by athree-electrode electric discharge device which is connected betweeneach of the printing segments of a distributor and the correspondingprinter selector magnets. The grid .electrodes of the electric dischargedevices are 1927. Serial No. 206,813. 1

connected directlyt the printing segments,- and the printer magnets *areinserted 'in the plate circuits. The impulses are further lengthened bya condenser connected to the grid of each electric discharge device.This condenser serves to store `charges similar to those on the gridsand to retain the Vcharges on the grids until the corresponding printerselector magnets have had sulicient time to operate. -In attaining theobject of this invention, a Ahigh speed printer relay is arranged at thereceiving'station to respond to incoming signal impulseswhich in a highspeed system, are of very short duration, and to thereby connect ordisconnect positive bat/- tery to alternate segments of a ring on arotary distributor. `This ring is divided into long segmentscorresponding in number to the channels employed in the system and isconnected by means of a rotatable brush to a second ring which islike\vise divided` into segments but of considerably shorter lengths.The second ring is provided with ten segments for each channel, thealternate seg ments of which are connected to the grids and theirassociated condensers. rl`he second ring is connected by mea-ns of asecond rotatable brush, referred to herein as a restore brush, to athird ring which is connected to negative battery, so that negativepotential will normally be applied to the grids and the condensers. Therestore brush rotates in advance ot the printer brush and shouldl therebe a positive charge remaining on any of the grid condensers from aprevious signal impulse, it will be discharged thereby restoring tonormal the printer magnet maintained operated by the positive charge. Inthis manner the positive operation and positive release of the printermagnets is assured.

(not shown) by means of a submarinegcable 1. The stations are eachprovided with special rotary distributors which are arranged to i shownand this section is shown developed for rotate in synchronism inaccordance with practice Well known in the art. Of the distributor atstation X only the receiving section is the sake of clea'rness.I Cablelis shown terminating in the input circuit of a space discharge or othertype of amplifier 2. -To the output circuit of the amplifier there isconnected through a vibrating relay lcircuit 3 of the type disclosed in'U'. S. vPatent-"1,680,550,

granted'to M. B. Kerr-on Aug. 14, 1928, a high .speedd printer relay 4which is arranged to respond to the amplified incoming signals Relay 4is of the unbiased polarized type and l is designed to be responsive toimpulses of Aboth positive and negative polarity, the relay armaturebeing arranged to remain in engagement with either of its associatedcontacts until an impulse of the polarity opposite tothat which lastactuated it, is received by the relay. The armature of relay 4 isconnected t'o the positive pole of grounded battery 5 and its associatedcontacts are respectively connected to two groups of alternate segmentsof a ring 6 of the receiving section of the distributor. The distributorhas in its receiving section three parallel rings, 6, 7 and 8. Ring 6consists o'f segments corresponding' in numberito the number v,otchannels provided for transmission, one segment A being provided'foreach channel; ring is a -one group being provided continuous memberandis connected tothe negative side of batter 9, the purpose of whichwill be 4hereina ter explained; and ring 8 consists of groups of 10segments each, for each' channel for the purpose 'of recelvmg theimpulses y thereof. Rings 6 and 8 are Vinterconnected fio ` from asecond source 19 by a rotatable brush 10 and rings 7 and 8 areinterconnected by a rotatable brush 11, the latter brush being arrangedto rotate from left to right in advance of the fformer brush Of ring 8the segments for the first channel only are shown connected foroperationand those designated by even numbers are respectively connecimd to thegrids of a series of three-electrode vacuum tubes 12, 13, 14, 15 and 16,while the odd numbered segments are left dead in order to permit ofsomephase wander of the distributor brushes withrespect to incomingsignals. The filaments of the vacuum tubes are furnished withalternating current from a common source 17 through transformer 18, andthe plate circuits are likewisefurnished with alternating current, butthrough transformer 20. It is understood, of course, that direct currentmay be furnishedv instead of the alternating current, in which event,the transformers will be eliminated. but inasmuch as each channelrequires-live vacuumftubes and there may be several channels provided,the alternectcd totrans'former 'proper )base and no message natingcurrent is' preferable. Respectively included in the plate circuits of13, 14, 15 and 16 are printer magnets 21,- 22, 23, 24 and 25 andcondensers 26, 27, 28, 29 and 30, the condensers being necessary onlyinthetubes 12,.

cases where alternating current is usedin the filament and platecircuits. Respectively connected in the input4 circuits-of the vacuumtubes and arranged in parallel with thegrids thereof, are condensers 31,32, 33, 34 and 35 'which are arranged to receive'chargesfsimultaneouslywith .their respectively associa-ted grids and to prolong the charges onthe rids after the respective grid circuits have een opened.

shown for the first channel together with their respectively associatedcondensers and' printer magnets, is identical with the arrangementrequired in the remaining channels,the filaments of the vacuum tubes ofboth the odd and even numbered channels being connected to transformer18 at points37 and 3 9. -The plate circuits of the vacuum tubes-areconchannels being connectedat point 38 and -the odd numbered channelsbeing connected atv point 40.

20, the' even numbered When the distributors are .operating inl on theca le, spacing signals only are received in relay 4 the polarity of thelatter signals reversing at order to effect a substantial balance ofpolarities and provide reversals for correction.l In

va four-channel system this balance would be perfect because the spacingsignals in the signals are the beginning of each channel Vin first andthird channels arevof one polarity and those in thesecondand Vfourth areofy the other polarity, but in a five channel system there would be afifth channel and the spacing signals thereof would be of the samepolarityas that of the first and third channels, thereby causing apreponderance of one po.- larity over the other polarity.V Thispreponderance of polarity -is corrected somewhat balance obtained by amethand a substantial od disclosed in' U. S. Patent `No. 1,695,040Agranted to A. A.

method for obtaining a satisfactory balance in a five-channel vysteimitis assumed'for the lio Glo'key on Dec. l1, 1928.. In order to avoidunnecessary discussion .of the purpose ofdescribing the operation of theinvention in a clear `and=simple manner, that the system comprises four.channels and that the spacing signalsv received in relay 4 are positivein the first 'and third channels 'and negative inthe second d fourthchannels,

it being understood off ourse that the markl 1n signals in each po arityto the spacing signals." en message sigpals are on the cable comnnel areopposite in binations of spacin `|`and marking signals are respectivelyrecelv d in the variouschannels in the order the. positions of thelcorrelao' L. `The arrangementV of the vacuum tubes y ammo andB until thecurrent of the signal impulses reverses. It will be noted that contact'Ais connected in multiple to theirst and third segments of ring 6 andcontact B is similarly connectedto the second-and fourth segments.

' Assuming that the distributor at X is in synchronism and ,phase withthe distributor at the distant office', and that the message isbci'ngrreceived in the first channel, the spacing signals which are ofpositive polarity would -cause the armature to engage contact B, but

contact B is not connected'to the first channel segment of ring 6 andtherefore the'spacing signals would cause a charge to be impresse thefirst and third channels.

'segment 2' the circuit closed by brush on any of the storing grids andcondensers. But should a marking signal, which would be a negativeimpulse in this case, be received,

the armature would engage Contact A, and inasmuch as this Contact isconnected to the first vchannel segment of ring 6 a circuit will beclosed as brush 1Q makes. contact with the even numbered segment of ring8 corresponding in position in the channel-to the impulse which actuatedthe armature to-produce a positive impulse as will be hereinafterexplained. 4lin a similar manner the marking vsignals in the remainingchannels are repeated as positive impulses although these signals asreceived over the cable are positive in the second and fourth channelsand negative 1n The operation of the arrangement shown for the firstchannel will now be described and this description will suiiice for theremaining channels. For this purpose an arbitrary .combination ofsignals received over the'irst channel Will be selected. Assuming thatthe combinationselected consists of imrelay 4in response to the firstimpulse which in this casehappens to be a marking signal, causes itsarmature t'o engage contact A and as brush 10 makes contact with segment2.0i4

ring 8, a positive charge from battery 5 is impressed on the grid ofvacuum tube 12 and condenser 31 in a circuit having parallel pathsextendingto ground connection 36 as vshown in the drawing. The positivecharge on the grid ordinarily allows sufficient space l current to fiowin the plate circuit to operate selector magnet 21, and as brush 10 passo 1s opened, but the charge on condenser 31 begins to discharge slowlythrough vacuum tube 12 and' thereby maintains the grid pos1t1ve with'respect to its associated filament so that the space current isprolonged sufiiclently to insure the operation of the magnet. The secondimpulse of the combination which is positive, isa spacing signal in-this channel and causes the armature of relay 4 to engage contact B,whereof no charge isimpressed on the grid of tube 13 when brush 10reaches segment 4 of ring 6. The thirdariel fourth impulses of thecombination are both negative and cause the armature to move back tocontact A and remain there for the diiration ot` the two'impulses. Asbrush 10 engages segments 6 and 8 in succession, positive charges aresuccessively impressed on the grids of tubes 14 and 15 and theirrespectively associated condensers 33 and 34, and selector magnets 23and 24 operate in amanner similar to that described for magnet 21. Thefifth impulse is positive which causes the relay armature to engagecontact B 'and thereby opens a circuit extending through the rst channelsegment of ring 6 and the segment 10 of ring -8. Therefore no charge isimpressed on the grid of tube 16 and the magnet 25 remains normal. Themagnets 21, 23 and 24 are therefore o erated in response to the markingsignals o the above combination and may remain in this condition becauseof the` charges retained on their respectively associated condensers 31,33 and 34, even after-the character, p or letter, corresponding to thecombination, Y

has been set up mechanically by the printer (not shown) and brush 1()has passed on to the -segments of the second channel.

A restore brush 11 which rotates in ad- Vance of brush 10 serves tomomentarily conneet ring 7' with each of segments 2, 4, 6, 8,

10 of ring 8 in succession and thereby a negative battery 9 which isconnected to ring 7 causes a negative charge to b e impressed on each ofthe condensers 31, 32, 33, 34 and 35. Should any of the condensers stillretain a portion of a positive charffe stored by thel precedingcombination of signal impulses, the connection of negative battery 9through brush 1l will effect the completedischarge and restore thecondensers to their normal condition. The potential normally applied tothe plates of the tubes through transformers 18and 20 is such that witha negative llO potential on the grids, insufficient space current Howsin the plate circuits to allow the magnets to remain operated andtherefore magnets 21, 23 and 24 release. The printer then restores themechanism which has been set up by the printer magnets in readiness fora new combination.

Since the input circuits of the vacuum tubes are of'extremely highresistance, the condensers which are connected in shunt lthereto andarrangedi-ito discharge therethrough, will discharge very slowly therebyallowing the marking signals to be'lengthfned over periods ofconsiderable' duration. In this manner relatively cheap slow-speedprinter magnets may be employed without impair-ing high speedtransmission.

. said receiving device and intermittently. connected'to said line.

2. In a transmission system, apparatus for increasing the effectivelength of signalimpulses comprising a distributor, a 'brush and segmentson said distributor, a condenser connected intermittently to saidsegments, and

-a vacuum tube relay having its input electrode connected to saidcondenser, whereby the output current of said relay attains a requiredvalue when the brush engages a segment, and remains at said required-value uni-il the distributor brush engages its next segment.

In a transmission system, means responsive toimpulses of short duration,slow ac ting devices, and thermi'onic' and capacity elementsrespectively co-acting therewith for lengitening said impulsessutliciently to operate said devices.

4. In -a transmission system, means responsive to lmpulses of shortduration recurring in rapid succession, slow acting devices, thermionicdevices for lengthening said impulses suliciently to operate said slowacting devices without alfecting said responsive means and other meansfor increasing the duration of .said lengthened impulses to insuretheoperation of said slow acting devices.

' 5. In a transmission system, means responsive to short impulses of onepolarity recurring in rapid succession, means for repeating saidimpulses as impulses of another polarity, slow acting devices,thermionie devices for lengthening said repeated impulses suiiicientlyto respectively operate said slow acting devices without affecting saidresponsive means and other means connected in parallel with saidthermionic devices for increasing the durationof said lengthenedimpulses `to insure the operation of said slow acting devices. l

6. In a transmission system, means responsive to short impulses of onepolarity recurring in rapid succession, means for repeating saidimpulses as impulses of another polarity, slow acting devices, electron4discharge devices for lengthening said repeated impulses sufficientlyto operate said slow acting devices ,without affecting said responsivemeans, and means coacting with said electron discharge devices forrestoring said slow acting devices to normal immediately after theyoperate. I r

7. In a transmission system, a line, apparatus for .receiving from saidline impulses of short duration recurring -in rapid succession, slowacting devices, and electron discharge devices for lengthening saidimpulses Sullieiently to-operate said slow acting devices withoutaffecting the reception'of impulses of .short duration.

without atlecting" the high speed transmis-V sion. 9. In a transmissionsystem, apparatus for receiving high speed signals, slowacting de-lvices, thermionic electrostatic means for lengthening said high speedsignals sufficientlyto operate said devices without affecting the highspeed transmission, and other electrostatic means for increasing theduration ofsaid lengthened impulses to insure the operation of saiddevices.

10. In an impulse receiving system, slow acting magnets, a vacuum tubedevice having its grid-cathode circuit connected to a' circuit-fromwhich impulses are received and its anode-cathode circuit operativelyconnected to said magnets, and acondenser connected in shunt to saidgrid-cathode circuit, said condenser being of capacity suitable tocausel the production of impulses lengthened with respect to thereceived impulses Vfor 0p-l erating said magnets in said anode-cathodeCircui 11. In a transmission system, apparatus for receiving high speedsignals, slow acting recording devices, thermionic means for lengtheningsaid high speed signals sufficiently to operate said recording deviceswithout affecting the high speed transmission, and other means arrangedto cooperate with said therinionic means for increasing the duration ofsaid lengthened impulsesto insure the opi era-tion of said devices. I l

12. In a transmission system, a loaded cable adapted for highspeedsignaling, apparatus forreceiving signals from said cable, slow actingrecording devices, and thermionic means and electrostatic' meanscooperating therewith-for lengthening saidhigh s eed signalssuiiiciently to. operate said recor in devices without afecting the highspee transmission.

13. In a transmission` system, a loaded cable adapted for high speedsignaling, -apparatus for receiving 'from said cable high speed signalsof'one polartyand repeating said signals as signals of another polarity,slow acting devices responsive to said repeated signals, and meanscomprising thermionic' and capacity elements for lengthening saidrepeated-signals suiiciently to operate said devices without affectingthe high speed signaling. Y, l 14. In a transmission system, a loadedcablehapparatus comprising means for rey peat certain of said incomingsignals of opposite polarities as signals of one polarity, slow actingdevices responsive to signals of only one polarity, and an elect-rondischarge device and a condenser co-acting therewith for lengtheningsaid repeated signals sufficiently to operate said devices 16. In atransmission system, apparatus comprising means for receiving .highspeed signals, means for distributing certain of said signals over aplurality of channels, slow actingrecording devices in each of saidchannels, and separate thermionic means and condensers co-actingrespectively therewith for lengthening'said certain signals in eachchan-l nel, said means being capable of lengthening the signalssuliiciently to operate the recording devices in their respectivechannels without affecting high speed transmission.

17. In a transmission. system, a loaded cable, apparatus comprising;lmeans for receiving from said cable high speed signals of oppositepolarities and repeating certain of saidsignals of both polarities assignals of only one polarity, means for distributing the repeatedsignals overa plurality of channels` slow acting recording devices ineach of said.

channels comprising electron discharge devices and condensers.respectively co-acting therewith, and means individual to said channelsfor lengthening said high speed repeated signals sufliciently to operatetheir respec- 4tively associated recordingr devices without affectinghigh speed transmission.

18. In a transmission system, a loaded cable, receiving apparatuscomprising a high speed relay responsive to signals of oppositepolarities incoming from said cable,'contacts and armature of said relayarranged to repeat said incoming signals as signals of one polarity,means for distributing the repeated signals over a plurality ofchannels, slow acting recording devices in each of said ehannelsresponsive to signals of only one polarity, and electron dischargedevices and condensers respectively arranged in parallel therewith ineach of said channels Jfor lengthening said repeated signals suiicientlyto operate the slow acting devices in their respective channels withoutaiiecting the speed of transmission 192 In a transmission system,apparatus comprising means responsive to high speed current impulses ofopposite polarities and arranged to repeat certain of said impulses asimpulses of one polarity, electron-disvcharge devices each comprising afilament,

grid, and a plate electrode arranged to receive and lengthen-saidrepeated impulses. a slow acting recording device connected in the platecircuit of cach ot said 'electron discharge devices, and arranged torespond to impulses of one polarity only, means for successivclyapplying to the grids of cach of said elect-ron discharge devices afterthe recording devices respectively connected to said discharge devices,have operated. an impulse of the oppositepolarity to eii'ectvthedischarge of the grids and the release of therecording devices.

20. In a transmission system, apparatus comprising a relay responsive tohigh speed current impulses of opposite polarities, contacts andarmatureofsaid relay arranged to repeat certain of said impulses as impulses ofpositive polarity, electron discharge devices arranged to receive andlengthen said repeated impulses, each of said devices comprising afilament, a grid and a plate elec* trode, a condenser connected inparallel with each of said grids for further lengthening of saidrepeated signals, a slow acting recording device connected in circuit toeac-h plate electrode and arranged to respond to said repeated signals,and means for applying animpulse of negative polarity to each of saidgrids to discharge any positive charge thereon and to thereby effect therelease of the associated recording devices. l

21. In a transmission system, a relay responsive to current impulses ofpositive polarities, armature and contacts on said relay, a source ofpotential connected to said armature for repeating certain of saidimpulses as impulses of one polarity, a rotary distributor for repeatingsaid repeated signals over a plurality of channels, a ring on saiddistributor comprising a plurality of segments corresponding to thenumber of channels employed, said segments being arranged in two groupsof alternate segments, one group being connected to one of said contactsand another group being connected to the other of said contacts, asecond ring on saidv distributor 'comprising a plurality of segmentsarranged in groups corresponding in number to the number of channelsemployed, arotatable brush for successively connecting the 22. Ina'transmission system, apparatus` for receiving highspeed signals ofopposite polarities and repeating certain of said impulses as impulsesof positive polarity,V a distributor for distributinglthe re eated imlrality'of segments arranged in groups correspondin in number tothenumber of seg'- ments o the frst mentionediring and the other iscontinuous, the repeated impulses im-v4 pressed on the distributorthrough the segments of the .first mentioned "ring, electron dischargedevices each comprising a filament, a grid-and a plate electrode andconnected rea set kof three rings, one j selectively to the segmentsofthe'secondmem tloned ring, a rotatable brush interconnecting each ofsaid plate electrodes, the space current between the electrodes of. eachof said dis-x charge devices being'efective to lengthen said repeatedimpulsesof positive polarity sufficientlyt'o operate said-recordingdevice.

In witness whereof, I hereunto subscribe 'my name this 18th day of JulyA. 19,27'.-

. i WILLIAM, A.. KNooP.l

-20 slow acting recor 'ngz device in circuit with

